NOTE: I’m not an expert on the best ways to utilize Dupont connectors; I’m just sharing what has worked for me.
One of the more frustrating things for me as an “electronics beginner” was the problem of making dependable connections between separate devices at the circuit level.
Prototyping on a solder-less breadboard is a breeze with purpose-made jumper wires, even though it can get to be a little confusing…
…and it’s fairly easy to create custom breadboard wires when the time is right:
You might even say that soldering up a permanent version of a circuit on perfboard or a PCB isn’t all that difficult:
But how do you deal with connections to devices or components that aren’t on the same board? Some kind of standardized connector would sure be nice. Enter …
What’s a “Dupont connector”? The most familiar example may be the female connectors that you see on the ends of ribbon cable:
Here is a slightly different example, with female connectors on one end and male connectors on the other end:
Here’s yet another variation:
OK, so you’ve either seen them before or you haven’t. Here’s an up-close view of the male variety…
…and an under-the-covers view:
Looking at the previous two photos, you can visualize how a flexible “tab” in the plastic housing snaps into place after the “box-y” part of the metal connector is inserted past it. The tab normally keeps the connector from pulling back out of the housing, but with a small enough screwdriver (or other pointy tool) you can gently lift the tab and remove the connector. That’s a useful feature when you need to reconfigure things.
“Sure”, you say, “but how does the connector get attached to the wire in the first place? No doubt it requires a fancy, techno-magical machine.”
I guess you could call it that, but most folks just refer to it as a “crimping tool” or “crimper”.
Here’s how it works:
- You pull out your box of Dupont (and other?) connector supplies, and
- Decide whether you need a male pin or a female socket. (Notice that the outer ends of both items are identical.)
- In either case, you bend the base of the connector back and forth until it breaks away from the retainer strip.
- Next, you close your ratcheting crimper tool a click or two and insert the connector into the appropriate opening:
- Use your thumbnail to make sure the end of the connector is even with the outer surface of the crimper jaw.
- Now for the tricky part – inserting the wire to the right depth before “committing to the crimp”. This photo shows a wire with a reasonable amount of insulation stripped off, aligned with both to-be-crimped sections of the connector.
- Now go ahead and insert the wire. “OK, but how do I know when it’s at the right depth? It’s really hard to see in there.” The trick I use is to angle the wire slightly so the end of the insulation catches on the connector section that will be crimped around the exposed wire. In other words, I use my eyes to get in the neighborhood, and then register the final depth by feel.
- Finally, without allowing the wire to move in the connector, squeeze the handles of the crimping tool tightly. The “full cycle ratchet” feature of my crimper won’t allow the jaws to re-open until they have been fully closed. That removes the need for guesswork. When the jaws DO open again, the crimped connection usually stays lodged in the upper jaw. I grip the wire close to the tool and push it downward, away from the jaw, to pop it out. Voila!
- Insert the connector into a Dupont housing of your choice, and ENJOY!
Here is one fun example of a DIY adapter set for a 9V battery using Dupont connectors:
In retrospect, it may have been better to use female sockets for the “base” connection, to prevent accidental short circuits. But this is the way I use the cable most of the time … your mileage may vary:
After discovering Dupont connectors, I started ordering each size of plastic housing: single-wire, double-wire, etc. By the time I got to 4-wire housings, the prices began to feel “skewed”. I skipped over several sizes at that point, and bought a set of 16-wire housings which allow me to make any custom-size housing I will probably ever need, like so:
- I use my scrollsaw to cut through the housing at the desired width. This wastes one wire position, but it’s still much cheaper per wire this way.
- I smooth off the ragged sides with a sanding disc, but you could also pass the housing back-and-forth against a piece of regular sandpaper that’s lying on a stiff, flat surface.
With this method I can make things like the 6-to-6 pin cable below, for connecting a CP2102-based USB-to-TTL-serial converter to an Arduino Pro Mini board. All I had to do was separate a 6-wire group from a rainbow cable, remove the single-wire (or was it 3-wire?) housings, and push the exposed female connectors into my homemade 6-wire housings. Nice!